# name : frollmean from data.table, fast roll mean (moving average)
# key : frollmean@data.table
# contributor: Shuguang Sun
# --
frollmean(${1:x}, ${2:n}, alog = \"${3:$$(yas-choose-value '("fast" "exact")), align = \"${4:$$(yas-choose-value '("right" "left" "center"))}\"}\"$0)